As fundamental research in biology increasingly focuses on events occurring at the macromolecular level, structural studies at molecular and supramolecular levels become especially important. Electron microscopy provides high resolution structural information, which exceeds in resolution and a span of applications even most advanced light microscopic approaches. The major limitation of electron microscopy, its applicability only to "dead" samples, can be partially overcome by correlating the structural organization of a fixed sample with its dynamic behavior recorded prior to fixation using light microscopic approaches. This electron microscopy core unit will supply electron microscopy services for the program including sample preparation and analysis by a variety of electron microscopy techniques. The core will also develop advanced techniques in correlative light and electron microscopy specifically suited for the investigation of molecular motors and vesicle trafficking in cells and in cell-free motility systems. These new techniques will be also made available to the core users.